Pneumatic tool.



PTBNTED JUNE 4, 1907.

HfR. PRINDLE. PNEUMATIC T001.. APPLICATION FILED PEB. 26. 190B.

.am I @A201/mag s OF PHlL-ADELPHIA, PENNSJLLVANJT Ji.

PNEUltflATlC TOOL.

ne. seance.

Specification of Letters atent.

Patented June 4, 1907.

Application filed February 26,1906. Serial No. 303,072.

ih @Zt whom, it may concer-rv,.-

Be it known that l, HAROLD RiT'rENHoUsE liNDLE/of Philadcl hia, in the county of Philadelphia, and int 1e State of Pennsylvania, have invented a certain new and useful improvement in Pneumatic Tools; and l do hereby declare that the following is a full, clear, and exact description thereof, reference beimy had to the accompanying drawings, in which v Figure l is a lonoitudinal section of a pneumatic tool embodying m invention, the parts being shown in position when the pilston has just delivered its blow, and is ready to return Fig. 2 is a similar view showing the position of the parts just after the piston has commenced to move 1n the direction to strike the blow; 3 is a similar vie'W to Fig.v 1,

. but showing a portion only or" the tool to illustrate a spring-actuated valve; Fig. 4 is a horizontal section on the 'line 4-4 of F ig. l; Fig. 5 is a hori intel section on the line 5-5 of Fig. l ,1 ani-ghig. t; a horizontal section on the line 6-6 of F 1g. l.

The object of my invention is to provide a lpneumatic tool which, among other advan tages, will be economical in the consumption of an', will have an ample exhaust to avoid working againstbackressure, and have a valve mechanism relie le in its action, and of few parte, so that it may be easily assembled and taken to pieces, and to these ends, my invention consists in the pneumatic tool having the vconstruction substantially as hereinafter specified and claimed.

The tool in whicli'll have embodied my invention, and which has been selected for illustration, is a pneumatic hammer having a chambered body or cylinder A, of the usual form, a hammer B-reciprocable therein and consisting of a sim le cylindrical block and a rip form handle L, one end of the cylinder being the hammer being threaded internally for the coupling together of the cylinder and handle, as usual. The handle C has an' air passage c is controlled by afthrottle valve c, con i a lever cZ yadapted to be actuated, as is usual, hy the hand gripping the handle. The valve c consists ci' a simple cylindrical rod or bar reciprocabie a cylindrical cavity or chamber extending transversely of the handle with which the air inlet o communicates at one end, the rod intermediate its end being reduced in diameter to provide an annular space for the passage air into the threaded externally and the shank ofl valve chamber c3 which contains the valvev D which, as usual,automatically controls the i supply of aix' under pressure to opposite ends of the piston B vto reciprocate the same. One of the ends of Ithe rod coacts with an air inlet c, and constitutes the valve proper, and it is yieldingly held in closed position by means of a coil spring c, one end of whichis situated in a cavity in suoli end of the rod and the other bears against a screw plug which closes the transverse passage'in the handle. by the operating lever c2. My throttle va ve is extremely sim le and inexpensive, and may be most readlily placed in and removed from position. l

The' valve D is c lindrical i'n shape, and is hollowed or chamliered longitudinallyv from end to end, and it is reciprocable in a cylindrical valve box E situated in the chamber or cavity c3 in the handle shank or stem and placed between a disk or cap F that closes the cylinder A at one end, and a disk or cap G at the end of the chamber or cavity in the handle stem or shank, into which air flows when the fthrottle valve is open. One or more ports ol lead from the throttle valve chamber into said end of the chamber c3. The valve D at its end nearest the cap plate G has an nnulai' flange d, and about its midlength it as la similar flange d, the annular space between said flanges constituting an air passage, and said flanges are of the same diameter and slidingly fit the interior of the valve box. Contiguous to the other plate or disk F the valve box has an inwardly )rejecting shoulder or flange e whose internal diameter is the same as the external diameter of the valve, so that the latter is slidably fitted therein at its inner end. Between the midlength valve ange d and the Valve box is provided. l

Ports or assages H lead from the end of llangcs d and d', and a port or assage I leads from said annular space tot e end of the cylinderl A reached by the hammer B in completing its travel in striking the blow. A port or passage K leads from one of the ports or assaves H to the annular space etween t e va veI mid-length flange d and the valve box flange e to supply air under ressure'to such space, and a port or pass e l also leads to such annular space from liga flange e a second air space around the valve the valve c amber c3 into which air enters to the annular space between the valve l The other end or' lthe rod is enga ed lOO zie

vcylinder A at a point near the end thereof reached b v the hammer B tn striking al blow, the hammer thus closing eomnittni' cation of the cylinder .and such vport l, a short while before reaching lts stroke tn deltvcrtng a blow, and uncovering 1t a short [While after commencing its travel in the opto which air is supplied Vto ntove the hammer I in the diret-tion to strike its blow. For tlte egress of exhaust to the atmosphere` there are a series of ports which are tn eommu- `nieation with and lead from the end of the valve chamber m which the valve flange fl is located to the ,eltatnbeiL/, from which plate and valve (l, shown in Fig. l, would )e employed, and for the substitution of the spring for thepin, it. would be necessary merely to plug up the guiding openittg in tlte cap G provided foftlte use of the pitt.

The operation of tn v tool is-as follows l/Vith the parts shown in Fig l, where the hammer has just delivered its ,blow and is about to return, live air from the handle passing into the valve box through the ports g 8 will enter the anular space between tlte ports lead to the exterior' of the tool, and

there are a series of ports f) that lead from the other end of the valve box to said chamber ci. There are also exhaust passages or ports P whieh lead from the t-,vlinder near the end thereof reached by the hammer in striking its blow, and which ari' preferably carried to a poittt so that their outlets are in communieatton. with said annular chamber c" to avoid a discharge ofI air on the ltand of the workman ltolding the tool.

The valve is moved in one diret-tion b v pressure upon tlte mid-length annular flange cl supplied from the port K. and to move it in the opposite direction l ma vl employ air ressure, using the eonstruetion illustrated 1n Fig. l, or spring pressure, using the construction illustrated in Fig. Si.. ln the con struetion illustrated in Fig. l, a rod or pitt Q is used extending axially of the valve with one end exposed to live air pressure.eoming from the throttle valve chamber, and the opposite end engaging a bearing in the fortn of a cross-bar r/2 at. the inner end of t be valve, the pin being supportedand guided b v an opening in the eap plate or diskt whit-h it slidinglv fits` 'l'lte pressure-reeeiving end of the pin is small in comparison with the pressure-reeeiving area -of tile flange d, so that. when air acts upon said 'lange d it will move the valve in opposition to the pressure on the pin. The point of enga-gement of' the pin and the valve is adv/antageous, since the pitt acts ott-thc vvalve without any tendency to bind or twist the sante.

When a spring Q is employed to move the valve in one direction, it may be applied as illustrated in. Fig. 3, where one end of it has a seat in the cap plate G and the other end hears against an inwardly turned annular flange dt at the inner end of the valve. The valve may be constructed so that it may be adapted for use either with the pin or the spring, so that in an emergency, or under any other conditions making it desirable, one may be substituted for the other. 1n this case, of course, the construction of cap flanges 1 and t/of the valve Dand passthenee into the ports I and enter therefrom the outer end of the cylinder. The hammer will thereb)Y be moved on its return stroke tothe opposite end of the cylinder under the pressure of tlte incoming air untilts end uncovers the exhaust ports P and the port l; whieh leads from the interior of the cylinder to the space between the valve flange d and the valve box flange e, thus removing pressure from the valve flange. Il', whereupon through the action of live air pressure upon the valveoperating pin Q, if it he used, or by the medttttn of the spring Q, if it bte used, the valve will shift. to tlte position shown in Fig. 2. Although the pressure of live air is removed from the hammer before the latter completes its return stroke, it will have acquired stiflicient momentum to carry it the. desired distance. in the cylinder on its return stroke. During tlte return stroke of the hammer, as described, the air in advance of the same will be exhausted froml the cylinder, passing therefrom through the ports M into the valve box, and soute of it will escape therefrom through the ports (l and some will pass through the valve and escape through the ports N. One of the features of my invention is the utilization of the chamber or passage through the valve for the .outlet ofv exhaust air. lt will be seen that the provision for the exhaust of' air is tnost abundant, and is sttelt that tlte hatmner is not working against an \v pressure. The valve being shifted tro the position shown in Fig. 2 places the inlet ports ll and the ports .\f which com- IIC municate with theleylinder in communieation b v means of the annular space between the valve flanges d and d', and the valve remains in such position, and live air acts vupon the hammer to move. it to strike the blow until the hammer, by its onward 'movement, covers the port L at the point where it opens into the cylinder, whereupon, by the access of air to the valve box between the valve flange tl and Ithe valve box flange c through the port K, the air from said port K acting upon the valve flange 1I will shift ity to the position shown in Fig. l, where it is maintained until, on the return stroke of' the hammer, as has already been described, the port L where it opens into the tn vlinder is again uncovered, and pressure from air entering through the port K is ,removed from the valve flange d.

Preferably, the opposing faces of the valve liange d and the valve llange box e a're rovided' with grooves for the admission o air, between them when thevalve is in the posi tion shown in Fig. 2. During the movementel' the hammer for striking a blow, as l haveA just described, air in advance of the hammer is exhausted from the cylinder through the ports P and also through the ports l, which, when the valve is in the position shown in Fig. 2, are uncovered Where they open into the outer end of the valve box. lt will be seen that an abundant provision for the exhaust oi air is also made'in my tool when t-he hammer is moving to strike its blow.

Home of the very desirable features of my tool have already been mentioned. Others are the small number of parts of the valve ineehanlsm; the form of the hammer, which is a simple cylindrical block, which, among' other advantages, possesses that oi being reversible because of the absence of grooves or special formation of it; and its abi ity-to dispose of particles of ire which, in out-door work in cold weather, forms in the valve meehanism, and which, in my tool, by the motion of the valve, are broken .u and because of the large exhaust ports W 'chl am able to employ, readily pass out of the tool.

Having thus described my invention, what l claim is* p l. ln a pneumatic tool, the combination of a valve box, a chambered valve therein communicating at its ends with'the interior of the valve box, an exhaust port leading from within the valve box at each end of the box, a piston-containing cylinder, and an exhaust port or ports leading therefrom to the valve box, and being in communication with the interior of the valve, air from said exhaust port passing to the atmosphere, in part directly through one of the exhaust ports at the end of the valve box, and impart through 'the valve to the exhaust port at the other end oi the valve box.

ln a pneumatic: tool, the combination of a valve box, a valve having an internal passage., having at one end an annular flange, and intermediate its ends an annular flange fitting the valve box, and an annular flange in the valve box at the end vof the valve opposite that having the flange, a live air passage leading to the space between the two valveA passage lea s, and an exhaust-,port in co`m-v munication With the interior of the valve.

3. In a pneumatic tool, the combination of a cylinder, a piston therein, a valve, passages controlledlbythe valve lead-ing to opposite ends of the cylinder, a passage from the cylinder to the valve adaptedl to 4be closed by the piston before completing its travel in one direction, two exhaust passages from the cy inder at'or near the same end thereof, but opening thereinto at different points along its length, and an exhaust passage from the other end of the cylinder.

` 4. In a pneumatic tool, the combination of a valve box, a hollow valve, the interior of the valve having a passage for exhaust, a pressure receiving surface on the exterior of the valve, alive air port leading to such surface to deliver iluid under pressure thereto, and means for applying power to the interior of the valve to move it in the opposite direction to that in which it is moved by pressure applied to said pressure-receiving surface. 5. In a pneumatic tool, the combination of a valve, a. ressure-receiving surface for moving the va ve' in one direction, a port for delivering live airto such surface, and means' for moving the valve in the op osite direction comprising a pin acting on t e valve and having one end constantly exposed to air under pressure.

' 6. In a pneumaticy tool, the combination of a hollow valve, a pressure-receivin0f surface on the exterior of the valve, a port l'or delivering live air to said surface, and a pin having one end in engagement with the valve on the inside thereof, and the other end exposed to air under pressure.

In testimony that l. claim the foregoing l have hereunto set my hand.

HAROLD RITTENHOUSE PRTNDLE.

Witnesses CARRIE REDEKER, HARRY REDEKER.. 

